I should probably put my cards on the table and admit I've done it. Strangely, although over the years I've gained quite a bit of experience playing around sexually with other men, especially in swingers' clubs with my wife, I've only "taken the plunge" and actually fucked a guy once. I can't deny I enjoyed it, though nor can I say I've had much desire to do it again.
Conversely, I'vee never been fucked by a guy, though i don't completely rule it out. I have been pegged by my wife, and though it doesn't give me too much pleasure, nor is it disagreeable, so, in the spirt of "you only live once," I'v accepted a challenge from a guy we met with his wife at a swinger's club: he wants to fight me in the club "red zone" - with the winner then having the right to fuck the loser and his wife. Our wives are totally into the idea - I must be mad - but I also find it thrilling.